package com.inji.spark.biz.util;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.List;

import org.apache.commons.lang3.StringUtils;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
import org.codehaus.jackson.map.util.JSONPObject;
import org.codehaus.jackson.type.JavaType;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 简单封装Jackson，实现JSON String<->Java Object的Mapper.
 * 
 * 封装不同的输出风格, 使用不同的builder函数创建实例.
 * 
 */
public class JsonMapper {

  private static Logger logger = LoggerFactory.getLogger(JsonMapper.class);

  private ObjectMapper mapper;

  public JsonMapper(Inclusion inclusion) {
    mapper = new ObjectMapper();
    //设置输出时包含属性的风格
    mapper.setSerializationInclusion(inclusion);
    //设置输入时忽略在JSON字符串中存在但Java对象实际没有的属性
    mapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    //禁止使用int代表Enum的order()來反序列化Enum,非常危險
    mapper.configure(DeserializationConfig.Feature.FAIL_ON_NUMBERS_FOR_ENUMS, true);
  }

  /**
   * 创建输出全部属性到Json字符串的Mapper.
   */
  public static JsonMapper buildNormalMapper() {
    return new JsonMapper(Inclusion.ALWAYS);
  }

  /**
   * 创建只输出非空属性到Json字符串的Mapper.
   */
  public static JsonMapper buildNonNullMapper() {
    return new JsonMapper(Inclusion.NON_NULL);
  }

  /**
   * 创建只输出初始值被改变的属性到Json字符串的Mapper.
   */
  public static JsonMapper buildNonDefaultMapper() {
    return new JsonMapper(Inclusion.NON_DEFAULT);
  }

  /**
   * 创建只输出非Null且非Empty(如List.isEmpty)的属性到Json字符串的Mapper.
   */
  public static JsonMapper buildNonEmptyMapper() {
    return new JsonMapper(Inclusion.NON_EMPTY);
  }

  /**
   * 如果对象为Null, 返回"null".
   * 如果集合为空集合, 返回"[]".
   */
  public String toJson(Object object) {

    try {
      return mapper.writeValueAsString(object);
    } catch (IOException e) {
      throw NestedException.wrap(e);
    }
  }

  /**
   * 如果JSON字符串为Null或"null"字符串, 返回Null.
   * 如果JSON字符串为"[]", 返回空集合.
   * 
   * 如需读取集合如List/Map, 且不是List<String>这种简单类型时,先使用函數constructParametricType构造类型.
   * @see #constructParametricType(Class, Class...)
   */
  public <T> T fromJson(String jsonString, Class<T> clazz) {
    if (StringUtils.isEmpty(jsonString)) {
      return null;
    }

    try {
      return mapper.readValue(jsonString, clazz);
    } catch (IOException e) {
      throw NestedException.wrap(e);
    }
  }

  /**
   * 如果JSON字符串为Null或"null"字符串, 返回Null.
   * 如果JSON字符串为"[]", 返回空集合.
   * 
   * 如需读取集合如List/Map, 且不是List<String>这种简单类型时,先使用函數constructParametricType构造类型.
   * @see #constructParametricType(Class, Class...)
   */
  @SuppressWarnings("unchecked")
  public <T> T fromJson(String jsonString, JavaType javaType) {
    if (StringUtils.isEmpty(jsonString)) {
      return null;
    }

    try {
      return (T) mapper.readValue(jsonString, javaType);
    } catch (IOException e) {
      throw NestedException.wrap(e);
    }
  }
  
  @SuppressWarnings("unchecked")
  public <T> T fromJson(String jsonString, Class<?> parametrized, Class<?>... parameterClasses) {
    return (T) this.fromJson(jsonString, constructParametricType(parametrized, parameterClasses));
  }
  
  @SuppressWarnings("unchecked")
  public <T> List<T> fromJsonToList(String jsonString, Class<T> classMeta){
    return (List<T>) this.fromJson(jsonString,constructParametricType(List.class, classMeta));
  }
  
  @SuppressWarnings("unchecked")
  public <T> T fromJson(JsonNode node, Class<?> parametrized, Class<?>... parameterClasses) {
    JavaType javaType = constructParametricType(parametrized, parameterClasses);
    try {
      return (T) mapper.readValue(node, javaType);
    } catch (IOException e) {
      throw NestedException.wrap(e);
    }
  }
  
  @SuppressWarnings("unchecked")
  public <T> T pathAtRoot(String json, String path, Class<?> parametrized, Class<?>... parameterClasses){
    JsonNode rootNode = parseNode(json);
    JsonNode node = rootNode.path(path);
    return (T) fromJson(node, parametrized, parameterClasses);
  }
  
  @SuppressWarnings("unchecked")
  public <T> T pathAtRoot(String json, String path, Class<T> clazz){
    JsonNode rootNode = parseNode(json);
    JsonNode node = rootNode.path(path);
    return (T) fromJson(node, clazz);
  }

  /**
   * 構造泛型的Type如List<MyBean>, 则调用constructParametricType(ArrayList.class,MyBean.class)
   *             Map<String,MyBean>则调用(HashMap.class,String.class, MyBean.class)
   */
  public JavaType constructParametricType(Class<?> parametrized, Class<?>... parameterClasses) {
    return mapper.getTypeFactory().constructParametricType(parametrized, parameterClasses);
  }

  /**
   * 當JSON裡只含有Bean的部分屬性時，更新一個已存在Bean，只覆蓋該部分的屬性.
   */
  @SuppressWarnings("unchecked")
  public <T> T update(T object, String jsonString) {
    try {
      return (T) mapper.readerForUpdating(object).readValue(jsonString);
    } catch (JsonProcessingException e) {
      logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
    } catch (IOException e) {
      logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
    }
    return null;
  }

  /**
   * 輸出JSONP格式數據.
   */
  public String toJsonP(String functionName, Object object) {
    return toJson(new JSONPObject(functionName, object));
  }

  /**
   * 設定是否使用Enum的toString函數來讀寫Enum,
   * 為False時時使用Enum的name()函數來讀寫Enum, 默認為False.
   * 注意本函數一定要在Mapper創建後, 所有的讀寫動作之前調用.
   */
  public void setEnumUseToString(boolean value) {
    mapper.configure(SerializationConfig.Feature.WRITE_ENUMS_USING_TO_STRING, value);
    mapper.configure(DeserializationConfig.Feature.READ_ENUMS_USING_TO_STRING, value);
  }

  /**
   * 取出Mapper做进一步的设置或使用其他序列化API.
   */
  public ObjectMapper getMapper() {
    return mapper;
  }
  
  public JsonNode parseNode(String json){
    try {
      return mapper.readValue(json, JsonNode.class);
    } catch (IOException e) {
      throw NestedException.wrap(e);
    }
  }
  
  /**
   * 输出全部属性
   * @param object
   * @return
   */
  public static String toNormalJson(Object object){
    return new JsonMapper(Inclusion.ALWAYS).toJson(object);
  }
  
  /**
   * 输出非空属性
   * @param object
   * @return
   */
  public static String toNonNullJson(Object object){
    return new JsonMapper(Inclusion.NON_NULL).toJson(object);
  }
  
  /**
   * 输出初始值被改变部分的属性
   * @param object
   * @return
   */
  public static String toNonDefaultJson(Object object){
    return new JsonMapper(Inclusion.NON_DEFAULT).toJson(object);
  }
  
  /**
   * 输出非Null且非Empty(如List.isEmpty)的属性
   * @param object
   * @return
   */
  public static String toNonEmptyJson(Object object){
    return new JsonMapper(Inclusion.NON_EMPTY).toJson(object);
  }
  
  public void setDateFormat(String dateFormat){
    mapper.setDateFormat(new SimpleDateFormat(dateFormat));
  }
  
  public static String toLogJson(Object object){
    JsonMapper jsonMapper = new JsonMapper(Inclusion.NON_EMPTY);
    jsonMapper.setDateFormat("yyyy-MM-dd HH:mm:ss");
    return jsonMapper.toJson(object);
  }

}